Density Perturbations from Modulated Decay of the Curvaton

TL;DR

This paper investigates how density perturbations and their non-Gaussian features arise in models where the curvaton's decay rate depends on a light scalar field, unifying and extending previous scenarios.

Contribution

It introduces a model where the decay rate depends on a modulaton, providing new predictions for non-Gaussianity parameters and a unified framework for related models.

Findings

Predictions for f_NL and g_NL specific to the model.

Both modulaton and curvaton fluctuations can contribute to curvature perturbations.

Standard curvaton and modulated reheating scenarios are special cases of this model.

Abstract

We study density perturbations, including their non-Gaussianity, in models in which the decay rate of the curvaton depends on another light scalar field, denoted the modulaton. Although this model shares some similarities with the standard curvaton and modulated reheating scenarios, it exhibits interesting predictions for f_NL and g_NL that are specific to this model. We also discuss the possibility that both modulaton and curvaton fluctuations contribute to the final curvature perturbation. Our results naturally include the standard curvaton and modulated reheating scenarios as specific limits and are thus useful to present a unified treatment of these models and their variants.